Trickle-Down Solar Water Heating

In Harry Thomason's trickle-down solar water heater, invented and deployed in the 1960s, water trickles down valleys in a slanted  metallic solar absorber. Air separates the trickling water from a transparent cover.  Trickle down heaters are radically simpler than conventional pipe-and-plate solar water heaters. It is a bit of a mystery why they are now so little used.
Click here to see William Shurcliff's comparison of trickle-down and pipe-and-plate technology:   (HTML,PDF).  (First published in Shurcliff's book, "New inventions in low-cost solar heating--100 daring schemes tried and untried", pp. 100-105, Brick House Publishing Company, 1979, Andover, Mass.)

Click here For photographs and three articles on a building heated since 1984 by a Thomason trickle-down heater and storage system--the Pinnacle Road U.S. Customs border station in Richford, Vermont, on the U.S.-Canadian border. From Solar Today, January/February 2003.

Click here for a drawing of a storage system similar to the one that seems to have been used in the Pinnacle Road building.

Fairly detailed information about the design of  trickle-down solar water heaters, and other solar heating apparatus, may be found in Thomason's well written US patents. US Patent Office patent numbers and titles: (List generated by search argument IN/thomason-harry-e in the advanced search function of the USPTO web site)

(1) 5,103,802  Thermosyphon heat-storage and backup heat apparatus
(2) 4,852,547  Heat storage
(3) 4,369,764  Solar heat storage system
(4) 4,343,293  Solar domestic water heater
(5) 4,284,059  Heat storage and heat exchanger
(6) 4,265,219  Solar heating (cooling) system
(7) 4,158,358  Heat and cold storage apparatus
(8) 4,146,011  Solar energy
(9) 4,139,055  Solar heating (cooling)
(10) 4,134,544  Solar heating system
(11) 4,132,220  Solar energy collector
(12) 4,102,327  Solar heating (cooling) system
(13) 4,082,143  Solar energy
(14) 4,048,812  Solar-energy conserving
(15) 4,029,082  Heat and cold storage apparatus
(16) 3,989,031  Solar heat collector
(17) 3,980,130  Heat, cold and dry storage

You will need a TIFF Viewer such as CPC View to view patents in the USPTO database.